The Rich Communication Services program is a GSM Association (GSMA) program for the creation of inter-operator communication services based on IP Multimedia Subsystem (IMS) .[1][2][3] It is marketed by the GSMA under the brand name joyn™.[4]

Main features of RCS are:

Enhanced Phonebook: service capabilities and enhanced contacts information such as presence and service discovery.

Contents

The Rich Communication Suite (RCS) industry initiative [5] was formed by a group of leading industry players in 2007. In February 2008 the GSMA officially became the project ‘home’ of RCS and an RCS Steering Committee was established by the organisation.

The scope of the RCS Steering Committee’s work was to entail the definition, testing and integration of the diverse services in the application suite known as RCS. Some three years later, the RCS project released a new specification – RCS-e (e = ‘enhanced’), which included various iterations of the original RCS specifications. The GSMA programme is now called Rich Communication Services.[6]

RCS takes on board different services defined by e.g. 3GPP and Open Mobile Alliance (OMA) and combines them with the Enhanced Phonebook. This allows the service capabilities as well as presence information of the different recipients to be shown in the terminal phonebook application.

RCS reuses the capabilities of 3GPP specified IMS core system as the underlying service platform taking care of issues such as authentication, authorization, registration, charging and routing.

Five releases of the RCS specifications have been made to date. Each release expanded the scope of its predecessor.

Release 1

Offered the first definitions for the enrichment of voice and chat with content sharing, driven from an RCS enhanced address book.

The GSMA has defined a series of joyn specifications that define specific implementations of the underlying RCS specifications. The RCS specifications often define a number of options for implementing individual communications features, resulting in challenges in delivering interoperable services between carriers. The joyn specifications aim to define a more specific implementation that promote standardisation and simplify interconnection between carriers.

At this time there are two major relevant releases:

joyn Hot Fixes - based upon the RCS 1.2.2 specification (previously known as RCS-e), this includes 1:1 chat, group chat, MSRP file sharing and video sharing (during a circuit switched call). Services based upon this specification are live in Spain, France and Germany.

joyn Blackbird Drop 1 - based upon the RCS 5.1 specification, this extends the joyn Hot Fixes service to include HTTP file sharing, location sharing, group file sharing, and other capabilities such as group chat store and forward. joyn Blackbird Drop 1 is backward compatible with joyn Hot Fixes. Vodafone Spain's network is accredited for joyn Blackbird Drop 1, and Telefónica and Orange Spain have also been involved in interoperability testing with vendors of joyn Blackbird Drop 1 clients. A number of client vendors are accredited to joyn Blackbird Drop 1.

Two or more future releases are planned:

joyn Blackbird Drop 2 - also based upon the RCS 5.1 specification, this will primarily add IP voice and video calling. The test cases for joyn Blackbird Drop 2 have yet to be released by the GSMA.

The RCS Interop and Testing (IOT) accreditation process [17] was started by the GSMA in order to improve the quality of testing, increase transparency, drive scale, minimize complexity and accelerate time-to-market (TTM) of joyn services. Companies need to undertake the IOT process from the GSMA to apply for a license to use the service mark joyn.

"Accredited" means that the device, client or network has undertaken a series of test cases (150 to 300) in a specific set of conditions, provided test results and traces that have been analysed by the GSMA RCS IOT team and any IOT issues arising resolved with the submitter.[18]

"Accreditation Ready" is the designation awarded to a hosted RCS service that has undertaken the same series of test cases as mobile network operator operator, provided test results and traces that have been analysed by the GSMA RCS IOT team and any IOT issues arising resolved with the submitter. This designation is used to allow operators to identify hosted solutions that will allow them to be become "Accredited" rapidly.[18]